関連する実験動画
Updated: May 12, 2026
10:59
Analysis of Translation Initiation During Stress Conditions by Polysome Profiling
Published on: May 19, 2014
リボソームのA部位からタンパク質合成を開始する
J E Wilson1, T V Pestova, C U Hellen
1Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305, USA.
Cell
|August 31, 2000
まとめ
この研究は,クリケット麻痺ウイルスの内部リボソームのエントリーサイトがAサイトから翻訳を開始し,イニシアター転送RNA (tRNA) とイニシアーション因子の必要性を回避できることを明らかにしています. この発見は,リボソームがエウカリオットにおけるタンパク質合成をどのように開始するかについての理解を広げています.
科学分野:
- 分子生物学は分子生物学である.
- ウイルス学 ウイルス学 ウイルス学
- 遺伝学 遺伝学とは
背景:
- リボソームがメッセンジャーRNA (mRNA) に結合することは,通常,イニシアター転送RNA (tRNA) がP部位のスタートコドンに結合することを含む.
- このプロセスはエウカリオットイニシアーションファクター2 (eIF2) によって媒介され,グアノシン三酸塩 (GTP) の水解を必要とします.
研究 の 目的:
- クリケット麻痺ウイルスの内部リボソームエントリーサイト (IRES) での翻訳開始のメカニズムを調査する.
- カノニカル翻訳開始因子とスタートコードンの認識が,IRESによる翻訳に不可欠であるかどうかを判断する.
主な方法:
- ウイルスのIRES内のPサイトコドンのサイト指向型変異.
- 修正されたIRESから生成されたタンパク質製品の分析.
- イニシエーターtRNA,eIF2,GTPの必要性を評価するための生化学分析.
主要な成果:
- クリケットの麻痺ウイルスIRESは80Sリボソームを形成し,イニシアターtRNA,eIF2またはGTPの水解なしに翻訳を開始しました.
- Pサイトコドンの突然変異は翻訳を廃止せず,それが解読されていないことを示しています.
- タンパク質配列解析は,Aサイトコドン (GCU) から翻訳が開始されたことを確認しました.
結論:
- 翻訳の開始はリボソームのA部位から起こり,従来のモデルに異議を唱えます.
- ウイルスのIRES要素は,定規の宿主因子とは独立して,翻訳開始のための代替メカニズムを使用することができます.
- この発見は,ユカリオットmRNAにおける翻訳されたオープン読み取りフレームの潜在的レパートリーを拡大する.
関連する概念動画
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
01:31Translation
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
01:27Ribosomes
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome production. Within...
02:33Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
01:29Translation in Prokaryotes
Prokaryote translation is a complex, highly coordinated process that converts genetic information from mRNA into functional proteins. It involves three stages: initiation, elongation, and termination, each facilitated by specific molecular components.Initiation of TranslationThe process begins with the assembly of the ribosomal subunits and initiation factors on the mRNA. In bacteria, the 30S ribosomal subunit recognizes the Shine-Dalgarno sequence in the mRNA, a conserved region upstream of...